Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.

In a large mixing bowl, combine softened butter and granulated sugar. Beat on medium speed until light and fluffy, about 2-3 minutes.

Add the egg and blend until fully integrated, about 1 minute. Scrape down the bowl as needed.

In a separate bowl, whisk together flour, baking powder, and salt. Mix thoroughly before adding to the wet ingredients.

Gradually add the dry mixture into the butter mixture, mixing on low until just combined.

Divide the dough into 3-4 parts and mix in Jello gelatin powder until fully incorporated.

Chill the dough wrapped in plastic wrap for 15-20 minutes.

Roll tablespoon-sized amounts of dough into balls, coat in sugar, and flatten slightly.

Place on baking sheets, leaving space between. Bake for 8-10 minutes until edges are set.

Cool on the baking sheet for 2 minutes before transferring to a wire rack to cool completely.